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This agenda includes important reminders, study hints, and summaries of lectures on atoms, molecules, water properties, polar and nonpolar compounds, organic compounds, functional groups, and macromolecules.
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AGENDA • Hand in Homework #1 • Hand in in-class work from last class • Questions / Concerns? • Lecture Quiz #2 • REMINDERS: • Pre-lab #3 due at beginning of lab period • Lab quiz #2 during lab • 1st four Microworlds due at end of lab today
Reminder: Exam next class! • Weeks 1-3 • Chapters 1-3, 10.1-10.5
Study Hints • Study in several shorter sessions • Write down answers to the Course Objectives for the chapters 1-3. • Answer them IN YOUR OWN WORDS using Vital Vocab (to be posted) • Make flash cards for Vital Vocab • Review the powerpoints and highlight Vital Vocab and definitions
Important Points from Lecture #2 • Atoms are made up of protons, neutrons and electrons. • The number of protons, neutrons and electrons give atoms their properties. • Molecules are made from atoms linked together by bonds
Lecture 3 Summary • Three bond types: • COVALENT - share electrons, strong • IONIC - transfer electrons, medium • HYDROGEN - form between partial charges (polar molecules), weak
Lecture 3 Summary • Properties of water: • Polar (hydrophobic sand demo) • “Sticky” - surface tension, capillary action • Ice floats • High specific heat • Universal solvent • Importance in body
Polar and Nonpolar • Polar = charged regions • “Like dissolves like” • polar wants to be near polar • Non-polar wants to be near non-polar
Organic Compounds CARBON HYDROGEN Structural formula Ball-and-stick model Space-filling model • Is stable with how many bonds? • Is stable with how many bonds? Methane The 4 single bonds of carbon point to the corners of a tetrahedron.
Organic Compounds CARBON • Is stable with how many bonds? Ethane Propane Carbon skeletons vary in length.
Organic Compounds CARBON • Is stable with how many bonds? 1-Butene 2-Butene Skeletons may have double bonds, which can vary in location.
Organic Compounds CARBON • Is stable with how many bonds? Cyclohexane Benzene Skeletons may be arranged in rings.
Why is the structure of carbon important? • Almost infinite variety of possible structures for biological molecules HYDROCARBONS – composed of only hydrogen and carbon
Exact structure of molecules is important • Structure = Function • ANIMATION: Campbell Ch 4 – L_dopa_A
Functional Groups • Groups of atoms attached to the carbon skeleton of molecules • Determine the properties of organic compounds • Part of molecule that participates in chemical reactions
Functional Groups • Five main functional groups in biology: • Hydroxyl group • Carbonyl group • Carboxyl group • Amino group • Phosphate group • These groups are all polar and make compounds containing them hydrophilic
WHAT ATOMS MAKE UP FUNCTIONAL GROUPS? WHY IS EACH OF THESE FUNCTIONAL GROUPS POLAR?
Atoms in the Functional Groups • Stable with how many bonds? • OXYGEN • NITROGEN • PHOSPHOROUS (atomic # 15)
Small Molecule Small Molecule Small Molecule Small Molecule Chemical Building Blocks of Living Systems • Organic compounds • Contain at least one CARBON atom • Hydrocarbon + functional group • Small molecules combine to form large molecules (macromolecules) Organic Macromolecule
Monomer Monomer Monomer Monomer Monomers vs Polymers • Monomer (1 small molecule) usually has 1 functional group • Polymer has many functional groups: • Can interact with many other things • Can perform a more complicated function
Connecting and Un-connecting • Dehydration synthesis • removal of a water molecule • Connects two monomers • Forms COVALENT BOND • Hydrolysis • addition of a water molecule • Disconnects two monomers • http://science.nhmccd.edu/biol/dehydrat/dehydrat.html
Connecting Short polymer Unlinked monomer Dehydration reaction Longer polymer New COVALENT bond
Un-connecting Hydrolysis Broken COVALENT bond
Four major classes of organic macromolecules • Carbohydrates • Nucleic acids • Proteins • Fatty Acids (lipids)
Carbohydrates • Monomer = monosaccharide • Structure • carbon, hydrogen, oxygen • (C1H2O1)n • Contains hydroxyl and carbonyl groups
Carbohydrates Structural formula Abbreviated structure Simplified structure
Carbohydrates • Functions • Store and release energy (glucose, starch) • Structural support (cellulose) • Examples = glucose, sucrose, lactose
Carbohydrates • MONOSACCHARIDE = one monomer of a carbohydrate • DISACCHARIDE = two monomers • TRISACCHARIDE = three monomers • POLYSACCHARIDE = many monomers Connected by WHAT kind of bond? ANIMATION: Campbell Ch 3 - Disaccharides
Polymer = Polysaccharides • Cellulose: Structure • Polysaccharides connected to form strands with hydrogen bonds • Starch: Energy storage • Glucose connected together to form a long chain
Structure = Function • Sweetness of sugars depends on the structure of the polysaccharide
Polarity • Are these sugars polar or non-polar? • What do sugars do in water?
Lipids • VARIOUS TYPES • Triglycerides • Phospholipids • Waxes • Steroids
Lipids - Triglycerides • Monomer = 3 fatty acids + glycerol • Structure: • Fatty Acids: Long hydrocarbon chains • Glycerol: hydrocarbons with hydroxyl (OH) groups
Lipids - Triglycerides • Function: Stores energy long-term
Polarity • Is a lipid polar or non-polar? • Does fat dissolve in water?
Saturated vs Unsaturated • Maximum number of hydrogensattached to carbons • No double bonds between carbons • More flexible • Straight • Packs tightly • More solid at room temperature
Saturated vs Unsaturated • Some carbons connected via double bonds • Fewer than maximum number of hydrogens • Less flexible (double bonds are stiffer) • Kinked • Does not pack tightly • Less solid at room temperature
Saturated vs Unsaturated ANIMATION: Campbell Ch 3 - Fats
Trans fats • Unsaturated fat made by partially hydrogenating an oil
Trans fats • Which will pack more tightly, a “cis” unsaturated fat or a “trans” unsaturated fat? • Which will be more solid at room temp? “cis” unsaturated fat “trans” unsaturated fat
Trans Fats - why are they bad? • Enzyme in the body that digests fats is less effective on trans unsaturated fats
Lipids - Phospholipids • Structure – Glycerol connected to TWO fatty acids and a phosphate group POLAR OR NON-POLAR?
Lipids - Phospholipids • Function: Makes up membranes in cells (phosphoplipids) Lipid bilayer:
Lipids - Waxes • STRUCTURE: Consist of a single fatty acid linked to an alcohol • FUNCTION: Form waterproof coatings
Lipids - Steroids • STRUCTURE: Have backbones bent into rings • FUNCTION: Are often hormones or the basis of hormones • EXAMPLE: Cholesterol
Lipids - Steroids • Naturally found in living things • Testosterone • Estrogen • Progesterone • Corticosteroids (regulate metabolism) • Found in other organisms - Insects have them
Lipids - Steroids • Anabolic Steroids – natural and synthetic versions of testosterone • Build up bone and muscle mass
Lipids - Steroids • Anabolic Steroids – natural and synthetic versions of testosterone • Build up bone and muscle mass • Can cause serious health problems